The present invention relates to a device for retrieval of defect closure devices and, more particularly, to a device for retrieving a closure device from a repaired site in the body of a patient in cases where the recovery of a condition of patient is not so well after repair operation of vascular defects or cardiac defects or where the closure device has fallen away or dislodged after operation.
At the present time, Fontan operations have been used for repair operations of complex cardiac anomalies such as single ventricle. In this operation, a single ventricle is used for the systemic circulation system, and for pulmonary circulation a vein of the systemic circulation system is directly connected to a pulmonary artery, whereby cardiac function is repaired. However, this operation frequently makes it difficult to perform postoperative management since a considerable decrease of cardiac output may occur because of increase of a pulmonary vascular resistance or transient ventricular hypofunction. The increase of pulmonary vascular resistance is caused by spasm of the pulmonary circulation system.
To avoid the increase of pulmonary vascular resistance and the considerable decrease of cardiac output, it is general practice for the above operation to form a small fenestration or perforation of about 4 mm between atria (most cases, the interatrial septum is made of an artificial membrane), thereby allowing the blood to flow through the small fenestration or perforation. This procedure followed by formation of the small fenestration or perforation is a Fontan fenestration. The closure treatment of the small fenestration after Fontan fenestration is mainly carried out by surgical operation. However, this surgical operation is followed by thoracotomy of a patient in addition to the treatment of the affected area. Thus, such surgical incision is a great burden to a patient. In particular, in case of a child patient, this burden is considerably large.
Recently, percutaneous transluminal therapeutic catheterization has been adopted as a noninvasive procedure to repair endocardial defects. For example, closure of atrial septal defects is carried out by transveneously inserting an intercardiac catheter into the heart and occluding the defect with an occluder. Further, the percutaneous transluminal therapeutic catheterization is applied to closure treatment of the small fenestration after Fontan fenestration with a closure device.
However, in case of the closure treatment of the small fenestration after Fontan fenestration with the closure device of the prior art, adhesion of thrombus may result from a large closure plate. Thus, there is a high risk of complications. Further, in cases where the closure device has fallen away or dislodged after operation, it is difficult to retrieve the closure device due to shape or size of the closure device.